One reason that all security training must be well documented is:

While human resources may utilize training documentation for onboarding or compliance purposes, this is not the primary reason for maintaining records of security training. The focus of security training documentation is more about liability and compliance rather than simply serving HR functions.

Documenting security training can help in budget discussions, but the primary goal is not financial justification. Budgeting decisions can be made based on various factors, and the legal protection afforded by well-documented training is a far more critical reason for its necessity.

Promulgating company policies is indeed important, but it is not the main reason for documenting security training. While training can communicate policies, the documentation's primary purpose lies in providing legal protection and demonstrating due diligence in employee training to prevent potential security breaches.